Question

Sample project -Android Studio connected with Sqlite databse or by using Mysql also .

create an sign-in app where students could

login with ( student id and password)

register with ( name ,student id and password,email)

also the possiblity for the student to change his password .

that app must be connected to your database

DO NOT ANSWER BY SENDING A CODE WRITING BUT WITH A SCREENSHOTS OF YOUR WORK WITH ALL DETAILS INSIDE .

Answer 1

1. First Of All we will create Registration Xml According to the Fields you mentioned(You can add your themes and also creativity to it if you want it basically a designing part).

Following will be the structure:-

Preview 20% Pixel 28 > C Name Student Id Email Password Confirm Password REGISTER Gradle O Preview Palette

Code For the same(activity_register.xml):-

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/nestedScrollView"
    android:background=""
    android:padding="20dp"
    tools:context="activities.LoginActivity">

    <android.support.v7.widget.LinearLayoutCompat
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <android.support.v7.widget.AppCompatImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:layout_marginTop="40dp"
            android:src="@drawable/logo" />

        <android.support.design.widget.TextInputLayout
            android:id="@+id/textInputLayoutName"
            android:layout_width="match_parent"
            android:textColorHint="#000000"
            android:layout_height="wrap_content"
            android:layout_marginTop="40dp" >

            <android.support.design.widget.TextInputEditText
                android:id="@+id/textInputEditTextName"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="@string/hint_name"
                android:inputType="text"
                android:maxLines="1"
                android:textColor="@color/colorText" />
        </android.support.design.widget.TextInputLayout>

        <android.support.design.widget.TextInputLayout
            android:id="@+id/textInputLayoutStudentId"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textColorHint="#000000"
            android:layout_marginTop="20dp" >

            <android.support.design.widget.TextInputEditText
                android:id="@+id/textInputEditTextStudentId"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="@string/hint_sid"
                android:inputType="text"
                android:maxLines="1"
                android:textColor="@color/colorText" />
        </android.support.design.widget.TextInputLayout>

        <android.support.design.widget.TextInputLayout
            android:id="@+id/textInputLayoutEmail"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textColorHint="#000000"
            android:layout_marginTop="20dp" >

            <android.support.design.widget.TextInputEditText
                android:id="@+id/textInputEditTextEmail"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="@string/hint_email"
                android:inputType="text"
                android:maxLines="1"
                android:textColor="@color/colorText" />
        </android.support.design.widget.TextInputLayout>

        <android.support.design.widget.TextInputLayout
            android:id="@+id/textInputLayoutPassword"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textColorHint="#000000"
            android:layout_marginTop="20dp" >

            <android.support.design.widget.TextInputEditText
                android:id="@+id/textInputEditTextPassword"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="@string/hint_password"
                android:inputType="textPassword"
                android:maxLines="1"
                android:textColor="@color/colorText" />
        </android.support.design.widget.TextInputLayout>

        <android.support.design.widget.TextInputLayout
            android:id="@+id/textInputLayoutConfirmPassword"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textColorHint="#000000"
            android:layout_marginTop="20dp" >

            <android.support.design.widget.TextInputEditText
                android:id="@+id/textInputEditTextConfirmPassword"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="@string/hint_confirm_password"
                android:inputType="textPassword"
                android:maxLines="1"
                android:textColor="@color/colorText" />
        </android.support.design.widget.TextInputLayout>

        <android.support.v7.widget.AppCompatButton
            android:id="@+id/appCompatButtonRegister"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="40dp"
            android:textColor="@color/colorText"
            android:background="@color/colorTextHint"
            android:text="@string/text_register" />

        <android.support.v7.widget.AppCompatTextView
            android:id="@+id/appCompatTextViewLoginLink"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="30dp"
            android:gravity="center"
            android:text="@string/text_member"
            android:textSize="16sp"
            android:textColor="@color/colorText" />

    </android.support.v7.widget.LinearLayoutCompat>

2. Now moving on to Login XML(I have Implemented with email you can make some changes to get it to student id though both are unique):-

Structure:-

Preview 28 Pixel 20% > Email Password LOGIN Palette

code for the same(activity_login):-

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/nestedScrollView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".activities.LoginActivity">

    <android.support.v7.widget.LinearLayoutCompat
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <android.support.v7.widget.AppCompatImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:layout_marginTop="40dp"
            android:src="@drawable/logo" />

        <android.support.design.widget.TextInputLayout
            android:id="@+id/textInputLayoutEmail"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textColorHint="#000000"
            android:layout_marginTop="40dp" >

            <android.support.design.widget.TextInputEditText
                android:id="@+id/textInputEditTextEmail"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="@string/hint_email"
                android:inputType="text"
                android:maxLines="1"
                android:textColor="@color/colorText" />
        </android.support.design.widget.TextInputLayout>

        <android.support.design.widget.TextInputLayout
            android:id="@+id/textInputLayoutPassword"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textColorHint="#000000"
            android:layout_marginTop="20dp" >

            <android.support.design.widget.TextInputEditText
                android:id="@+id/textInputEditTextPassword"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="@string/hint_password"
                android:inputType="textPassword"
                android:maxLines="1"
                android:textColor="@color/colorText" />
        </android.support.design.widget.TextInputLayout>

        <android.support.v7.widget.AppCompatButton
            android:id="@+id/appCompatButtonLogin"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="40dp"
            android:textColor="@color/colorText"
            android:background="@color/colorTextHint"
            android:text="@string/text_login" />

        <android.support.v7.widget.AppCompatTextView
            android:id="@+id/textViewLinkRegister"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="30dp"
            android:gravity="center"
            android:text="@string/text_not_member"
            android:textSize="16sp"
            android:textColor="@color/colorText" />

        <android.support.v7.widget.AppCompatTextView
            android:id="@+id/forgotPassword"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="20dp"
            android:gravity="center"
            android:text="Forgot password?"
            android:textSize="16sp"
            android:textColor="@color/colorText" />

    </android.support.v7.widget.LinearLayoutCompat>
</android.support.v4.widget.NestedScrollView>

3. Forgot Password Screen Xml

Structure:-

Pixel 28 13% + > Email CONFRM Palette

code for the same(activity_forgotpassword):-

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/nestedScrollView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".activities.LoginActivity">

    <android.support.v7.widget.LinearLayoutCompat
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <android.support.v7.widget.AppCompatImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:layout_marginTop="40dp"
            android:src="@drawable/logo" />

        <android.support.design.widget.TextInputLayout
            android:id="@+id/textInputLayoutEmail"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textColorHint="#000000"
            android:layout_marginTop="40dp" >

            <android.support.design.widget.TextInputEditText
                android:id="@+id/textInputEditTextEmail"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="@string/hint_email"
                android:inputType="text"
                android:maxLines="1"
                android:textColor="@color/colorText" />
        </android.support.design.widget.TextInputLayout>


        <android.support.v7.widget.AppCompatButton
            android:id="@+id/appCompatButtonConfirm"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="40dp"
            android:textColor="@color/colorText"
            android:background="@color/colorTextHint"
            android:text="Confirm" />


    </android.support.v7.widget.LinearLayoutCompat>
</android.support.v4.widget.NestedScrollView>

4. Confirm forgot password Xml

Structure of XML File

Pixel 28 25% >> C Password Confirm password RESET Palette

code for the same(activity_confirmforgotpassword):-

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/nestedScrollView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".activities.LoginActivity">

    <android.support.v7.widget.LinearLayoutCompat
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <android.support.v7.widget.AppCompatImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:layout_marginTop="40dp"
            android:src="@drawable/logo" />

        <android.support.design.widget.TextInputLayout
            android:id="@+id/textInputLayoutEmail"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textColorHint="#000000"
            android:layout_marginTop="40dp" >


            <android.support.design.widget.TextInputEditText
                android:id="@+id/textInputpass"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="Password"
                android:inputType="textPassword"
                android:maxLines="1"
                android:textColor="@color/colorText" />
        </android.support.design.widget.TextInputLayout>


        <android.support.design.widget.TextInputLayout
            android:id="@+id/textInputConfirmPass"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textColorHint="#000000"
            android:layout_marginTop="40dp" >

            <android.support.design.widget.TextInputEditText
                android:id="@+id/textInputConfirmPassword"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="Confirm password"
                android:inputType="textPassword"
                android:maxLines="1"
                android:textColor="@color/colorText" />
        </android.support.design.widget.TextInputLayout>


        <android.support.v7.widget.AppCompatButton
            android:id="@+id/appCompatButtonReset"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="40dp"
            android:textColor="@color/colorText"
            android:background="@color/colorTextHint"
            android:text="Reset" />


    </android.support.v7.widget.LinearLayoutCompat>
</android.support.v4.widget.NestedScrollView>

5. Activity for users xml:-

Contains No structure Only definition through code

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent"
    >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/text1"
        android:layout_marginTop="20dp"
        android:layout_marginLeft="20dp"
        android:textSize="20sp"
        android:textStyle="bold"
        android:padding="16dp"
        android:textColor="@color/colorText"/>

</LinearLayout>

Now Moving on to Colors.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="colorPrimary">#3F51B5</color>
    <color name="colorPrimaryDark">#303F9F</color>
    <color name="colorAccent">#FF4081</color>
    <color name="colorText">#FFFFFF</color>
    <color name="colorTextHint">#51d8c7</color>

</resources>

Styles and Strings Xml

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
    </style>

</resources>

<resources>
    <string name="app_name">SqliteLogin</string>
    <string name="hint_name">Name</string>
    <string name="hint_sid">Student Id</string>
    <string name="hint_email">Email</string>
    <string name="hint_password">Password</string>
    <string name="hint_confirm_password">Confirm Password</string>
    <string name="text_login">Login</string>
    <string name="text_register">Register</string>
    <string name="error_message_name">Enter Full Name</string>
    <string name="error_message_email">Enter Valid Email</string>
    <string name="error_message_age">Enter Age</string>
    <string name="error_message_password">Enter Password</string>
    <string name="success_message">Registration Successful</string>
    <string name="text_not_member">No account yet? Create one</string>
    <string name="text_already_member">Already a member? Login</string>
    <string name="error_email_exists">Email Already Exists</string>
    <string name="error_password_match">Password Does Not Matches</string>
    <string name="error_valid_email_password">Wrong Email or Password</string>
    <string name="text_member">Already a member? Login</string>
</resources>

As you have seen the structure of our register xml thus you can have a fair idea of what our Database is gonna Looklike,Moving on to it By creating Package sql in Java Portion:-

Code for Our DatabaseHelper in the sql Package:-

package com.delaroystudios.sqlitelogin.sql;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

import com.delaroystudios.sqlitelogin.model.User;

/**
 * Created by delaroy on 3/27/17.
 */
public class DatabaseHelper  extends SQLiteOpenHelper{

    private static final int DATABASE_VERSION = 1;

    private static final String DATABASE_NAME = "UserManager.db";

    private static final String TABLE_USER = "user";

    private static final String COLUMN_USER_ID = "user_id";
    private static final String COLUMN_USER_NAME = "user_name";
    private static final String COLUMN_USER_EMAIL = "user_email";
    private static final String COLUMN_USER_PASSWORD = "user_password";

    private String CREATE_USER_TABLE = "CREATE TABLE " + TABLE_USER + "("
            + COLUMN_USER_ID + " INTEGER PRIMARY KEY AUTOINCREMENT," + COLUMN_USER_NAME + " TEXT,"
            + COLUMN_USER_EMAIL + " TEXT," + COLUMN_USER_PASSWORD + " TEXT" + ")";

    private String DROP_USER_TABLE = "DROP TABLE IF EXISTS " + TABLE_USER;

    public DatabaseHelper(Context context){
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db){
        db.execSQL(CREATE_USER_TABLE);
    }

    @Override
    public  void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion){
        db.execSQL(DROP_USER_TABLE);
        onCreate(db);
    }

    public void addUser(User user){
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(COLUMN_USER_NAME, user.getName());
        values.put(COLUMN_USER_EMAIL, user.getEmail());
        values.put(COLUMN_USER_PASSWORD, user.getPassword());

        db.insert(TABLE_USER, null, values);
        db.close();
    }

    public void updatePassword(String email, String password){
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(COLUMN_USER_PASSWORD, password);
        db.update(TABLE_USER, values, COLUMN_USER_EMAIL+" = ?",new String[] { email });
        db.close();
    }

    public boolean checkUser(String email){
        String[] columns = {
                COLUMN_USER_ID
        };
        SQLiteDatabase db = this.getWritableDatabase();
        String selection = COLUMN_USER_EMAIL + " = ?";
        String[] selectionArgs = { email };

        Cursor cursor = db.query(TABLE_USER,
                columns,
                selection,
                selectionArgs,
                null,
                null,
                null);
        int cursorCount = cursor.getCount();
        cursor.close();
        db.close();

        if (cursorCount > 0){
            return true;
        }
        return false;
    }

    public boolean checkUser(String email, String password){
        String[] columns = {
                COLUMN_USER_ID
        };
        SQLiteDatabase db = this.getWritableDatabase();
        String selection = COLUMN_USER_EMAIL + " = ?" + " AND " + COLUMN_USER_PASSWORD + " =?";
        String[] selectionArgs = { email, password };

        Cursor cursor = db.query(TABLE_USER,
                columns,
                selection,
                selectionArgs,
                null,
                null,
                null);
        int cursorCount = cursor.getCount();
        cursor.close();
        db.close();

        if (cursorCount > 0){
            return true;
        }
        return false;
    }
}

Now User Class(Initialisation of Our Register Parameters):-

package com.delaroystudios.sqlitelogin.model;

/**
 * Created by delaroy on 3/27/17.
 */
public class User {

    private int id;
    private String name;
    private String sid;
    private String email;
    private String password;

    public User(String sid) {
        this.sid = sid;
    }

    public int getId(){
        return id;
    }

    public void setId(int id){
        this.id = id;
    }

    public String getName(){
        return name;
    }

    public void setName(String name){
        this.name = name;
    }
    
    public String getSid(){
        return sid;
    }

    public void setSid(String sid){
        this.sid = sid;
    }

    public String getEmail(){
        return email;
    }

    public void setEmail(String email){
        this.email = email;
    }

    public String getPassword(){
       return password;
    }

    public void setPassword(String password){
        this.password = password;
    }
}

Now Regiser_Activity.java

package com.delaroystudios.sqlitelogin.activities;

import android.os.Bundle;
import android.support.design.widget.Snackbar;
import android.support.design.widget.TextInputEditText;
import android.support.design.widget.TextInputLayout;
import android.support.v4.widget.NestedScrollView;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.AppCompatButton;
import android.support.v7.widget.AppCompatTextView;
import android.view.View;

import com.delaroystudios.sqlitelogin.R;
import com.delaroystudios.sqlitelogin.helper.InputValidation;
import com.delaroystudios.sqlitelogin.model.User;
import com.delaroystudios.sqlitelogin.sql.DatabaseHelper;

/**
 * Created by delaroy on 3/27/17.
 */
public class RegisterActivity extends AppCompatActivity implements View.OnClickListener {

    private final AppCompatActivity activity = RegisterActivity.this;

    private NestedScrollView nestedScrollView;

    private TextInputLayout textInputLayoutName;
    private TextInputLayout textInputLayoutSid;
    private TextInputLayout textInputLayoutEmail;
    private TextInputLayout textInputLayoutPassword;
    private TextInputLayout textInputLayoutConfirmPassword;

    private TextInputEditText textInputEditTextName;
    private TextInputEditText textInputEditTextLayoutSid;
    private TextInputEditText textInputEditTextEmail;
    private TextInputEditText textInputEditTextPassword;
    private TextInputEditText textInputEditTextConfirmPassword;

    private AppCompatButton appCompatButtonRegister;
    private AppCompatTextView appCompatTextViewLoginLink;

    private InputValidation inputValidation;
    private DatabaseHelper databaseHelper;
    private User user;

    @Override
    protected void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_register);
        getSupportActionBar().hide();
        
        initViews();
        initListeners();
        initObjects();
    }

    private void initViews(){
        nestedScrollView = (NestedScrollView) findViewById(R.id.nestedScrollView);

        textInputLayoutName = (TextInputLayout) findViewById(R.id.textInputLayoutName);
        textInputLayoutSid = (TextInputLayout) findViewById(R.id.textInputEditTextStudentId);
        textInputLayoutEmail = (TextInputLayout) findViewById(R.id.textInputLayoutEmail);
        textInputLayoutPassword = (TextInputLayout) findViewById(R.id.textInputLayoutPassword);
        textInputLayoutConfirmPassword = (TextInputLayout) findViewById(R.id.textInputLayoutConfirmPassword);

        textInputEditTextName = (TextInputEditText) findViewById(R.id.textInputEditTextName);
        textInputEditTextLayoutSid = (TextInputEditText) findViewById(R.id.textInputEditTextStudentId);
        textInputEditTextEmail = (TextInputEditText) findViewById(R.id.textInputEditTextEmail);
        textInputEditTextPassword = (TextInputEditText) findViewById(R.id.textInputEditTextPassword);
        textInputEditTextConfirmPassword = (TextInputEditText) findViewById(R.id.textInputEditTextConfirmPassword);

        appCompatButtonRegister = (AppCompatButton) findViewById(R.id.appCompatButtonRegister);

        appCompatTextViewLoginLink = (AppCompatTextView) findViewById(R.id.appCompatTextViewLoginLink);
    }

    private void initListeners(){
        appCompatButtonRegister.setOnClickListener(this);
        appCompatTextViewLoginLink.setOnClickListener(this);
    }

    private void initObjects(){
        inputValidation = new InputValidation(activity);
        databaseHelper = new DatabaseHelper(activity);
        user = new User(textInputLayoutSid.toString());
    }  

    @Override
    public void onClick(View v){
        switch (v.getId()){
            case R.id.appCompatButtonRegister:
                postDataToSQLite();
                break;
            case R.id.appCompatTextViewLoginLink:
                finish();
                break;
        }
    }

    private void postDataToSQLite(){
        if (!inputValidation.isInputEditTextFilled(textInputEditTextName, textInputLayoutName, getString(R.string.error_message_name))) {
            return;
        }
        if (!inputValidation.isInputEditTextFilled(textInputEditTextEmail, textInputLayoutEmail, getString(R.string.error_message_email))) {
            return;
        }
        if (!inputValidation.isInputEditTextEmail(textInputEditTextEmail, textInputLayoutEmail, getString(R.string.error_message_email))) {
            return;
        }
        if (!inputValidation.isInputEditTextFilled(textInputEditTextPassword, textInputLayoutPassword, getString(R.string.error_message_password))) {
            return;
        }
        if (!inputValidation.isInputEditTextMatches(textInputEditTextPassword, textInputEditTextConfirmPassword,
                textInputLayoutConfirmPassword, getString(R.string.error_password_match))) {
            return;
        }

        if (!databaseHelper.checkUser(textInputEditTextEmail.getText().toString().trim())) {

            user.setName(textInputEditTextName.getText().toString().trim());
            user.setEmail(textInputEditTextEmail.getText().toString().trim());
            user.setPassword(textInputEditTextPassword.getText().toString().trim());

            databaseHelper.addUser(user);

            // Snack Bar to show success message that record saved successfully
            Snackbar.make(nestedScrollView, getString(R.string.success_message), Snackbar.LENGTH_LONG).show();
            emptyInputEditText();


        } else {
            // Snack Bar to show error message that record already exists
            Snackbar.make(nestedScrollView, getString(R.string.error_email_exists), Snackbar.LENGTH_LONG).show();
        }


    }

    private void emptyInputEditText(){
        textInputEditTextName.setText(null);
        textInputEditTextEmail.setText(null);
        textInputEditTextPassword.setText(null);
        textInputEditTextConfirmPassword.setText(null);
    }

}

Login Activity:-

package com.delaroystudios.sqlitelogin.activities;

import android.content.Intent;
import android.support.design.widget.Snackbar;
import android.support.design.widget.TextInputEditText;
import android.support.design.widget.TextInputLayout;
import android.support.v4.widget.NestedScrollView;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.AppCompatButton;
import android.support.v7.widget.AppCompatTextView;
import android.view.View;

import com.delaroystudios.sqlitelogin.R;
import com.delaroystudios.sqlitelogin.helper.InputValidation;
import com.delaroystudios.sqlitelogin.sql.DatabaseHelper;

public class LoginActivity extends AppCompatActivity implements View.OnClickListener {

    private final AppCompatActivity activity = LoginActivity.this;

    private NestedScrollView nestedScrollView;

    private TextInputLayout textInputLayoutEmail;
    private TextInputLayout textInputLayoutPassword;

    private TextInputEditText textInputEditTextEmail;
    private TextInputEditText textInputEditTextPassword;

    private AppCompatButton appCompatButtonLogin;

    private AppCompatTextView textViewLinkRegister;
    private AppCompatTextView textViewLinkForgotPassword;

     private InputValidation inputValidation;
    private DatabaseHelper databaseHelper;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        getSupportActionBar().hide();

        initViews();
        initListeners();
        initObjects();
    }
    private void initViews(){
        nestedScrollView = (NestedScrollView) findViewById(R.id.nestedScrollView);

        textInputLayoutEmail = (TextInputLayout) findViewById(R.id.textInputLayoutEmail);
        textInputLayoutPassword = (TextInputLayout) findViewById(R.id.textInputLayoutPassword);

        textInputEditTextEmail = (TextInputEditText) findViewById(R.id.textInputEditTextEmail);
        textInputEditTextPassword = (TextInputEditText) findViewById(R.id.textInputEditTextPassword);

        appCompatButtonLogin = (AppCompatButton) findViewById(R.id.appCompatButtonLogin);

        textViewLinkRegister = (AppCompatTextView) findViewById(R.id.textViewLinkRegister);
        textViewLinkForgotPassword = (AppCompatTextView) findViewById(R.id.forgotPassword);
    }

    private void initListeners(){
        appCompatButtonLogin.setOnClickListener(this);
        textViewLinkRegister.setOnClickListener(this);
        textViewLinkForgotPassword.setOnClickListener(this);
    }

    private void initObjects(){
        databaseHelper = new DatabaseHelper(activity);
        inputValidation = new InputValidation(activity);
    }

    @Override
    public void onClick(View v){
        switch (v.getId()){
            case R.id.appCompatButtonLogin:
                verifyFromSQLite();
                break;
            case R.id.textViewLinkRegister:
                Intent intentRegister = new Intent(getApplicationContext(), RegisterActivity.class);
                startActivity(intentRegister);
                break;
            case R.id.forgotPassword:
                Intent intent = new Intent(getApplicationContext(), ForgotPassword.class);
                startActivity(intent);
                break;
        }
    }

    private void verifyFromSQLite(){
        if (!inputValidation.isInputEditTextFilled(textInputEditTextEmail, textInputLayoutEmail, getString(R.string.error_message_email))) {
            return;
        }
        if (!inputValidation.isInputEditTextEmail(textInputEditTextEmail, textInputLayoutEmail, getString(R.string.error_message_email))) {
            return;
        }
        if (!inputValidation.isInputEditTextFilled(textInputEditTextPassword, textInputLayoutPassword, getString(R.string.error_message_email))) {
            return;
        }

        if (databaseHelper.checkUser(textInputEditTextEmail.getText().toString().trim()
                , textInputEditTextPassword.getText().toString().trim())) {
            Intent accountsIntent = new Intent(activity, UsersActivity.class);
            accountsIntent.putExtra("EMAIL", textInputEditTextEmail.getText().toString().trim());
            emptyInputEditText();
            startActivity(accountsIntent);
            finish();
        } else {
            Snackbar.make(nestedScrollView, getString(R.string.error_valid_email_password), Snackbar.LENGTH_LONG).show();
        }
    }

    private void emptyInputEditText(){
        textInputEditTextEmail.setText(null);
        textInputEditTextPassword.setText(null);
    }
}

Forgot Password Activity class

package com.delaroystudios.sqlitelogin.activities;

import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.Snackbar;
import android.support.design.widget.TextInputEditText;
import android.support.design.widget.TextInputLayout;
import android.support.v4.widget.NestedScrollView;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.AppCompatButton;
import android.support.v7.widget.AppCompatTextView;
import android.view.View;
import android.widget.Toast;

import com.delaroystudios.sqlitelogin.R;
import com.delaroystudios.sqlitelogin.helper.InputValidation;
import com.delaroystudios.sqlitelogin.sql.DatabaseHelper;

/**
 * Created by delaroy on 3/3/18.
 */

public class ForgotPassword extends AppCompatActivity {

    private TextInputEditText textInputEditTextEmail;
    private TextInputLayout textInputLayoutEmail;

    private AppCompatButton appCompatButtonConfirm;

    private InputValidation inputValidation;
    private DatabaseHelper databaseHelper;

    private NestedScrollView nestedScrollView;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_forgotpassword);


        textInputEditTextEmail = (TextInputEditText) findViewById(R.id.textInputEditTextEmail);
        appCompatButtonConfirm = (AppCompatButton) findViewById(R.id.appCompatButtonConfirm);
        nestedScrollView = (NestedScrollView) findViewById(R.id.nestedScrollView);

        databaseHelper = new DatabaseHelper(this);
        inputValidation = new InputValidation(this);

        setTitle("Recover password");
        appCompatButtonConfirm.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                verifyFromSQLite();
            }
        });

    }

    private void verifyFromSQLite(){

        if (textInputEditTextEmail.getText().toString().isEmpty()){
            Toast.makeText(this, "Please fill your email", Toast.LENGTH_SHORT).show();
            return;
        }


        if (databaseHelper.checkUser(textInputEditTextEmail.getText().toString().trim())) {
            Intent accountsIntent = new Intent(this, ConfirmPassword.class);
            accountsIntent.putExtra("EMAIL", textInputEditTextEmail.getText().toString().trim());
            emptyInputEditText();
            startActivity(accountsIntent);
        } else {
            Snackbar.make(nestedScrollView, getString(R.string.error_valid_email_password), Snackbar.LENGTH_LONG).show();
        }
    }

    private void emptyInputEditText(){
        textInputEditTextEmail.setText("");
    }
}

Confirm Forgot Password :-

package com.delaroystudios.sqlitelogin.activities;

import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.Snackbar;
import android.support.design.widget.TextInputEditText;
import android.support.design.widget.TextInputLayout;
import android.support.v4.widget.NestedScrollView;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.AppCompatButton;
import android.view.View;
import android.widget.Toast;

import com.delaroystudios.sqlitelogin.R;
import com.delaroystudios.sqlitelogin.helper.InputValidation;
import com.delaroystudios.sqlitelogin.model.User;
import com.delaroystudios.sqlitelogin.sql.DatabaseHelper;

/**
 * Created by delaroy on 3/3/18.
 */

public class ConfirmPassword extends AppCompatActivity {
    private TextInputEditText textInputEditTextPassword;
    private TextInputEditText textInputEditTextConfirmPassword;

    private TextInputLayout textInputLayoutPassword;
    private TextInputLayout textInputLayoutConfirmPassword;

    private InputValidation inputValidation;
    private DatabaseHelper databaseHelper;
    private NestedScrollView nestedScrollView;
    private AppCompatButton appCompatButtonReset;

    String email;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_confirmpassword);

        inputValidation = new InputValidation(this);
        databaseHelper = new DatabaseHelper(this);

        textInputEditTextPassword = (TextInputEditText) findViewById(R.id.textInputpass);
        textInputEditTextConfirmPassword = (TextInputEditText) findViewById(R.id.textInputConfirmPassword);

        textInputLayoutPassword = (TextInputLayout) findViewById(R.id.textInputLayoutPassword);
        textInputLayoutConfirmPassword = (TextInputLayout) findViewById(R.id.textInputLayoutConfirmPassword);
        nestedScrollView = (NestedScrollView) findViewById(R.id.nestedScrollView);
        appCompatButtonReset = (AppCompatButton) findViewById(R.id.appCompatButtonReset);

        Intent intent = getIntent();
        email = intent.getStringExtra("EMAIL");

        setTitle("Reset password");

        appCompatButtonReset.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                updatePassword();
            }
        });
    }


    private void updatePassword() {

        String value1 = textInputEditTextPassword.getText().toString().trim();
        String value2 = textInputEditTextConfirmPassword.getText().toString().trim();

        if (value1.isEmpty() && value2.isEmpty()){
            Toast.makeText(this, "fill all fields ", Toast.LENGTH_LONG).show();
            return;
        }

        if (!value1.contentEquals(value2)){
            Toast.makeText(this, "password doesn't match", Toast.LENGTH_LONG).show();
            return;
        }

        if (!databaseHelper.checkUser(email)) {

            Snackbar.make(nestedScrollView, "email doesn't exist", Snackbar.LENGTH_LONG).show();
            return;

        } else {
            databaseHelper.updatePassword(email, value1);

            Toast.makeText(this, "password reset successfully", Toast.LENGTH_SHORT).show();
            emptyInputEditText();

            Intent intent = new Intent(this, LoginActivity.class);
            startActivity(intent);
            finish();
        }

    }

    private void emptyInputEditText()
    {
        textInputEditTextPassword.setText("");
        textInputEditTextConfirmPassword.setText("");
    }
}

As it is quite difficult to give explanation of each piece of code (in just 2 hrs) but i have tried best (firstly putting the XML structure in front of you So it will aid you in understanding most of the code in Java Class File).